Process for hardening gelatin

Abstract

A method for hardening gelatin is disclosed, which comprises incorporating in a gelatin-containing material at least one compound represented by formula (I) ##STR1## wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 each represents an alkyl group, an alkenyl group, an aralkyl group, or an aryl group, or any two of R 1 R 2 , R 3 , R 4 , R 5 , and R 6 are bound to each other to form a ring, or any three or more of them are bound to each other to form a condensed ring, X represents a group capable of being eliminated when the compound represented by formula (I) reacts with a nucleophilic reagent, and Y⊖ represents an anion.

What is claimed is: 
     
       1. A process for hardening gelatin which comprises incorporating in a gelatin-containing light-senstive silver halide photographic material at least one compound represented by formula (I) ##STR5## wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6  each represents an alkyl group, an alkenyl group, an aralkyl group, or an aryl group, or any two of R 1 , R 2 , R 3 , R 4 , R 5 , and R 6  are bound to each other to form a ring, or any three or more of them are bound to each other to form a condensed ring, X represents a group capable of being eliminated when the compound represented by formula (I) reacts with a nucleophilic reagent, and Y.sup.⊖ represents an anion. 
     
     
       2. A process for hardening gelatin as in claim 1, wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6  each represents a straight or branched chain alkyl group containing from 1 to 20 carbon atoms, an aralkyl group containing from 6 to 20 carbon atoms, or an aryl group containing from 5 to 20 carbon atoms. 
     
     
       3. A process for hardening gelatin as in claim 1, wherein at least one of R 1  and R 2 , R 3  and R 4 , and R 5  and R 6  are bound to each other to form a ring. 
     
     
       4. A process for hardening gelatin as in claim 3, wherein said ring is selected from the group consisting of a pyrrolidine ring, a piperadine ring, a perhydroazepine ring, a morpholine ring, and a pyrrole ring. 
     
     
       5. A process for hardening gelatin as in claim 1, wherein X is selected from the group consisting of a halogen atom, a sulfonyloxy group, a 1-pyridinyl group, an imidyloxy group, and an azolyloxy group. 
     
     
       6. A process for hardening gelatin as in claim 1, wherein Y.sup.⊖ is selected from the group consisting of a halide ion, a sulfonate ion, a sulfate ion, a phosphonate ion, a phosphate ion, BF.sup.⊖ 4 , ClO.sup.⊖ 4  and PF.sup.⊖ 6 . 
     
     
       7. A process for hardening gelatin as in claim 1, wherein Y.sup.⊖ is selected from the group consisting of Cl.sup.⊖, BF.sup.⊖ 4 , ClO.sup.⊖ 4 , PF.sup.⊖ 6 , and a sulfonate ion. 
     
     
       8. A process for hardening gelatin as in claim 1, wherein the hardener is used in an amount of from 0.01 to 20 wt % based on the weight of dry gelatin. 
     
     
       9. A process for hardening gelatin as in claim 2, wherein the hardener is used in an amount of from 0.01 to 20 wt % based on the weight of dry gelatin. 
     
     
       10. A process for hardening gelatin as in claim 3, wherein the hardener is used in an amount of from 0.01 to 20 wt % based on the weight of dry gelatin. 
     
     
       11. A process for hardening gelatin as in claim 4, wherein the hardener is used in an amount of from 0.01 to 20 wt % based on the weight of dry gelatin. 
     
     
       12. A process for hardening gelatin as in claim 5, wherein the hardener is used in an amount of from 0.01 to 20 wt % based on the weight of dry gelatin. 
     
     
       13. A process for hardening gelatin as in claim 6, wherein the hardener is used in an amount of from 0.01 to 20 wt % based on the weight of dry gelatin. 
     
     
       14. A process for hardening gelatin as in claim 1, wherein Y.sup.⊖ is bound to any of X, R 1 , R 2 , R 3 , R 4 , R 5 , and R 6  to form an inner salt.